public class eg4_1 {
    public static void main(String[] args) {
        Hammer hammer1 =new Hammer("羊角锤");
        Hammer hammer2 =new Hammer("平角锤");
        Nail nail1 = new Nail(5);
        Nail nail2 = new Nail(6);
        Nail nail3 =new Nail(7);
        hammer1.hit(nail1);
        hammer2.hit(nail2);
        hammer2.hit(nail3);

    }
}
